C#

[Serializable]
public class MyMouseEventArgs :EventArgs
{
    public MyMouseEventArgs(MouseButtons button, int clicks, int x, int y, int delta)
    {
        _Button = button;
        _Clicks = clicks;
        _X = x;
        _Y = y;
        _Delta = delta;
    }

    private MouseButtons _Button;
    private int _Clicks;
    private int _Delta;
    private int _X;
    private int _Y;

    public MouseButtons Button { get { return _Button; } }
    public int Clicks { get { return _Clicks; } }
    public int Delta { get { return _Delta; } }
    public Point Location { get { return new Point(_X, _Y); } }
    public int X { get { return _X; } }
    public int Y { get { return _Y; } }

    public static implicit operator MyMouseEventArgs(MouseEventArgs e)
    {
        return new MyMouseEventArgs(e.Button, e.Clicks, e.X, e.Y, e.Delta);
    }
    public static implicit operator MouseEventArgs(MyMouseEventArgs e)
    {
        return new MouseEventArgs(e.Button, e.Clicks, e.X, e.Y, e.Delta);
    }
}

class A
{
    public Guid Guid;
    public A()
    {
        Guid = Guid.NewGuid();
    }
}

static void Main(string[] args)
{
    var a = new A();
    Console.WriteLine(a.Guid);
    Foo(a);
    Console.WriteLine(a.Guid);
}

static void Foo(A par)
{
    Console.WriteLine(par.Guid);
    par = new A();
    Console.WriteLine(par.Guid);
}

static void Main(string[] args)
{
    var a = new A();
    Console.WriteLine(a.Guid);
    Foo(ref a);
    Console.WriteLine(a.Guid);
}

static void Foo(ref A par)
{
    Console.WriteLine(par.Guid);
    par = new A();
    // btw, you still can do something like par.Guid = Guid.NewGuid();
    Console.WriteLine(par.Guid);
}

deep@Pune wrote:

then what is the use of ref and out keyword here???

arimao wrote:

cannot allow users to leave the application